/Engine/Source/Editor/GameProjectGeneration/Public/GameProjectUtils.h
Returns true if the specified class name is properly formed and does not conflict with another class, including source/header files
static bool IsValidClassNameForCreation ( const [FString](API\Runtime\Core\Containers\FString) & NewClassName, const [FModuleContextInfo](API\Runtime\Projects\FModuleContextInfo) & ModuleInfo, const [TSet](API\Runtime\Core\Containers\TSet)< [FString](API\Runtime\Core\Containers\FString) > & DisallowedHeaderNames, [FText](API\Runtime\Core\Internationalization\FText) & OutFailReason )